lttng/org.eclipse.tracecompass.lttng2.ust.core/src/org/eclipse/tracecompass/lttng2/ust/core/analysis/debuginfo/UstDebugInfoBinaryAspect.java

   1 /*******************************************************************************
   2  * Copyright (c) 2015 EfficiOS Inc., Alexandre Montplaisir
   3  *
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *******************************************************************************/
   9
  10 package org.eclipse.tracecompass.lttng2.ust.core.analysis.debuginfo;
  11
  12 import static org.eclipse.tracecompass.common.core.NonNullUtils.nullToEmptyString;
  13
  14 import org.eclipse.jdt.annotation.Nullable;
  15 import org.eclipse.tracecompass.internal.lttng2.ust.core.analysis.debuginfo.UstDebugInfoLoadedBinaryFile;
  16 import org.eclipse.tracecompass.lttng2.ust.core.trace.LttngUstTrace;
  17 import org.eclipse.tracecompass.lttng2.ust.core.trace.layout.ILttngUstEventLayout;
  18 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  19 import org.eclipse.tracecompass.tmf.core.event.ITmfEventField;
  20 import org.eclipse.tracecompass.tmf.core.event.aspect.ITmfEventAspect;
  21 import org.eclipse.tracecompass.tmf.core.trace.TmfTraceUtils;
  22
  23 /**
  24  * Event aspect of UST traces that indicate the binary callsite (binary, symbol
  25  * and offset) from an IP (instruction pointer) context.
  26  *
  27  * Unlike the {@link UstDebugInfoSourceAspect}, this information should be
  28  * available even without debug information.
  29  *
  30  * @author Alexandre Montplaisir
  31  * @since 2.0
  32  */
  33 public class UstDebugInfoBinaryAspect implements ITmfEventAspect<BinaryCallsite> {
  34
  35     /** Singleton instance */
  36     public static final UstDebugInfoBinaryAspect INSTANCE = new UstDebugInfoBinaryAspect();
  37
  38     private UstDebugInfoBinaryAspect() {}
  39
  40     @Override
  41     public String getName() {
  42         return nullToEmptyString(Messages.UstDebugInfoAnalysis_BinaryAspectName);
  43     }
  44
  45     @Override
  46     public String getHelpText() {
  47         return nullToEmptyString(Messages.UstDebugInfoAnalysis_BinaryAspectHelpText);
  48     }
  49
  50     @Override
  51     public @Nullable BinaryCallsite resolve(ITmfEvent event) {
  52         /* This aspect only supports UST traces */
  53         if (!(event.getTrace() instanceof LttngUstTrace)) {
  54             return null;
  55         }
  56         LttngUstTrace trace = (LttngUstTrace) event.getTrace();
  57
  58         ILttngUstEventLayout layout = trace.getEventLayout();
  59
  60         /* We need both the vpid and ip contexts */
  61         ITmfEventField vpidField = event.getContent().getField(layout.contextVpid());
  62         ITmfEventField ipField = event.getContent().getField(layout.contextIp());
  63         if (vpidField == null || ipField == null) {
  64             return null;
  65         }
  66         Long vpid = (Long) vpidField.getValue();
  67         Long ip = (Long) ipField.getValue();
  68         long ts = event.getTimestamp().toNanos();
  69
  70         return getBinaryCallsite(trace, vpid.intValue(), ts, ip.longValue());
  71     }
  72
  73     /**
  74      * Get the binary callsite (which means binary file and offset in this file)
  75      * corresponding to the given instruction pointer, for the given PID and
  76      * timetamp.
  77      *
  78      * @param trace
  79      *            The trace, from which we will get the debug info analysis
  80      * @param pid
  81      *            The PID for which we want the symbol
  82      * @param ts
  83      *            The timestamp of the query
  84      * @param ip
  85      *            The instruction pointer address
  86      * @return The {@link BinaryCallsite} object with the relevant information
  87      */
  88     public static @Nullable BinaryCallsite getBinaryCallsite(LttngUstTrace trace, int pid, long ts, long ip) {
  89         /*
  90          * First match the IP to the correct binary or library, by using the
  91          * UstDebugInfoAnalysis.
  92          */
  93         UstDebugInfoAnalysisModule module =
  94                 TmfTraceUtils.getAnalysisModuleOfClass(trace,
  95                         UstDebugInfoAnalysisModule.class, UstDebugInfoAnalysisModule.ID);
  96         if (module == null) {
  97             /*
  98              * The analysis is not available for this trace, we won't be
  99              * able to find the information.
 100              */
 101             return null;
 102         }
 103         UstDebugInfoLoadedBinaryFile file = module.getMatchingFile(ts, pid, ip);
 104         if (file == null) {
 105             return null;
 106         }
 107
 108         /* Apply the path prefix defined by the trace, if any */
 109         String fullPath = (trace.getSymbolProviderConfig().getActualRootDirPath() + file.getFilePath());
 110         boolean isPIC = isPIC(fullPath);
 111
 112         long offset;
 113         if (isPIC) {
 114             offset = (ip - file.getBaseAddress());
 115         } else {
 116             /*
 117              * In the case of the object being non-position-independant (loaded
 118              * at a very low address), we must pass the actual 'ip' address
 119              * directly to addr2line.
 120              */
 121             offset = ip;
 122         }
 123
 124         return new BinaryCallsite(fullPath, file.getBuildId(), offset, isPIC);
 125     }
 126
 127     /**
 128      * Return if the given file (binary or library) is Position-Independent Code
 129      * or not. This indicates if addr2line considers the addresses as absolute
 130      * addresses or as offsets.
 131      */
 132     private static boolean isPIC(String filePath) {
 133         /*
 134          * Ghetto binary/library identification for now. It would be possible to
 135          * parse the ELF binary to check if it is position-independent
 136          * (-fPIC/-fPIE) or not.
 137          */
 138         return (filePath.endsWith(".so") || filePath.contains(".so.")); //$NON-NLS-1$ //$NON-NLS-2$
 139     }
 140
 141 }